Native Sign in with Apple fails with "Sign Up Not Completed" inside the AuthenticationServices sheet for every NEWLY registered App ID on our team (V4DCPCSM54) — including a clean-room probe App ID created via the ASC API with the capability enabled at creation — while an App ID registered in 2025 on the same team works. Entitlements, profiles, and capability config are all verified correct; capability toggle and fresh builds change nothing. This matches the server-side registration issue described in thread 790827. Filed as FB[23726069] with full details. Would appreciate DTS taking a look — this is currently blocking our App Store review (rejected 2.1(a)).